mirror of
https://github.com/enso-org/enso.git
synced 2024-12-24 03:02:30 +03:00
67 lines
2.5 KiB
Markdown
67 lines
2.5 KiB
Markdown
---
|
|
layout: developer-doc
|
|
title: Numbers
|
|
category: semantics
|
|
tags: [semantics, runtime, number]
|
|
order: 8
|
|
---
|
|
|
|
# Numbers
|
|
|
|
In order to enhance the user experience, Enso provides a number hierarchy,
|
|
encompassing both integers of unbound size and floating-point decimals.
|
|
|
|
<!-- MarkdownTOC levels="2,3" autolink="true" -->
|
|
|
|
- [Number Types](#number-types)
|
|
- [Internal Representation](#internal-representation)
|
|
- [Type Conversions](#type-conversions)
|
|
|
|
<!-- /MarkdownTOC -->
|
|
|
|
## Number Types
|
|
|
|
The base number type in Enso is `Number`. It includes both integers and
|
|
floating-point numbers and is the basic type that should be used whenever
|
|
numerical computations are performed. Any method defined on the type `Number` is
|
|
automatically available on all types of numeric values.
|
|
|
|
The hierarchy is further split into the `Integer` and `Decimal` types. `Integer`
|
|
is capable of representing values of unbound length. `Decimal` is capable of
|
|
representing IEEE 64-bit (double precision) floating numbers.
|
|
|
|
Any method defined on `Integer` is available for all integers, while any method
|
|
defined on `Decimal` is available on all floating-point numbers. Methods defined
|
|
on `Integer` or `Decimal` take precedence over methods defined on `Number`, when
|
|
name resolution is performed.
|
|
|
|
## Internal Representation
|
|
|
|
Integers that can be represented in a 64-bit integer type are represented as
|
|
such. When a 64-bit representation would overflow (either by the result of
|
|
creating a large number literal or an arithmetic operation), it is represented
|
|
in a Java `BigInteger` type, thus becoming significantly slower than the 64-bit
|
|
representation.
|
|
|
|
Decimals are represented using the Java `double` type.
|
|
|
|
## Type Conversions
|
|
|
|
Number literals that do not contain a decimal point, are treated as integers.
|
|
Other literals are interpreted as decimals (even if the fractional part is 0).
|
|
|
|
Any arithmetic operation where at least one of the operands is a decimal will
|
|
result in a decimal result.
|
|
|
|
Moreover, the default division operator `/` is implemented as floating-point
|
|
division and always returns a decimal. If the desired behavior is integral
|
|
division instead, the `Integer.div` method implements it.
|
|
|
|
Another operator worth noting is the exponentiation operator (`^`). It will
|
|
always result in a decimal whenever either operand is decimal or the exponent is
|
|
negative. It will also return a float result when the exponent is outside the
|
|
64-bit integer range.
|
|
|
|
There is a `Number.to_decimal` method, that allows converting any number to a
|
|
decimal. This is useful in certain high-performance and polyglot applications.
|